This invention concerns a device for reducing body heat loss and concomitantly diminishing the possibility of detection of the user thereof in cold weather environments.
Various suits and related garments have been developed whose insulative properties retain body heat and permit the wearers thereof to endure in the cold environments often experienced by hunters and military combat troops. While such suits achieve some degree of success for short exposure times, the insulation required for long exposure times becomes relatively thick, resulting in a heavy, bulky suit in which it becomes difficult to function.
Cold weather suits having battery powered heating elements are also well known. The limited life, expense and weight of such batteries, however, as well as the reduced efficiency thereof at very low temperatures are serious drawbacks to their use in battlefield conditions.
An additional problem encountered by hunters and military combat personnel is the possibility of their being detected in cold weather due to the so-called "white flagging effect", i.e. the formation of vapor clouds due to moisture in their exhaled breath.